Communications XML for Analysis is a Simple Object Access Protocol (SOAP)-based XML API, designed for standardizing data access interaction between a client application and a data provider working over the Web. Currently, under traditional data access techniques such as OLE DB and ODBC, a client component that is tightly coupled to a data provider server must be installed on the client machine in order for an application to be able to access data from the data provider. Tightly coupled client components, however, can create dependencies on a specific hardware platform, a specific operating system, a specific interface model, a specific programming language, and a specific match between versions of client and server components.
The requirement to install client components and the dependencies associated with tightly coupled architectures are unsuitable for the loosely coupled, stateless, cross-platform, and language independent environment of the Internet. To provide reliable data access to Web applications, the Internet, mobile devices, and cross-platform desktops, a standard methodology is required that does not require component downloads to the client. One possibility involves the Extensible Markup Language (XML) which is generic and can be universally accessed. Thus, instead of invoking a proprietary interface of a client component, it would be desirable for developers to call methods and transfer data through XML HTTP messages without any client components. It would also be desirable if the application developer could build client components without concern for tight coupling to a server component or application. Also, an application developed with any programming language and running on any platform, should be able to access data from any place on the Web without having to plan for specific platform support or even a specific provider version. One such vehicle for these and other network data access goals is provided by a protocol known as the Extensible Markup Language for Analysis or XMLA.
The protocol XML for Analysis advances the concepts of OLE DB by providing standardized universal data access to a standard data source residing over the Web without the need to deploy a client component that exposes Component Object Model (COM) interfaces. Additionally, XML for Analysis is optimized for the Web by minimizing roundtrips to the server and targeting stateless client requests to maximize the scalability and robustness of a data source. Much of the protocol with XMLA is related to two methods, Discover and Execute, which consume and send XML for stateless data discovery and manipulation.
Generally, XMLA protocol is built upon the open Internet standards of HTTP, XML, and SOAP, and is not bound to any specific language or technology. The specification references OLE DB so that application developers already familiar with OLE DB can easily determine how XML for Analysis can be mapped and implemented. Even though XMLA provides many advantages over previous architectures, there are still many applications that are not adequately covered by this protocol. These include current implementations of the Execute method as well as many features such as object design, parameter specifications, binary manipulations, and employment of other network protocols than HTTP, for example.